[PATCH 17/20] lpfc_debugfs: get rid of pointless access_ok()

From: Al Viro
Date: Sat May 09 2020 - 19:46:13 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

No, you do NOT need to "protect copy from user" that way.
Incidentally, your userland ABI stinks. I understand that you
wanted to accept "reset" and "reset\n" as equivalent, but I suspect
that accepting "reset this, you !@^!@!" had been an accident.
Nothing to do about that now - it is a userland ABI...

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
drivers/scsi/lpfc/lpfc_debugfs.c | 12 ------------
1 file changed, 12 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c
index 8a6e02aa553f..5a754fb5f854 100644
--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -2166,10 +2166,6 @@ lpfc_debugfs_lockstat_write(struct file *file, const char __user *buf,
char *pbuf;
int i;

- /* Protect copy from user */
- if (!access_ok(buf, nbytes))
- return -EFAULT;
-
memset(mybuf, 0, sizeof(mybuf));

if (copy_from_user(mybuf, buf, nbytes))
@@ -2621,10 +2617,6 @@ lpfc_debugfs_multixripools_write(struct file *file, const char __user *buf,
if (nbytes > 64)
nbytes = 64;

- /* Protect copy from user */
- if (!access_ok(buf, nbytes))
- return -EFAULT;
-
memset(mybuf, 0, sizeof(mybuf));

if (copy_from_user(mybuf, buf, nbytes))
@@ -2787,10 +2779,6 @@ lpfc_debugfs_scsistat_write(struct file *file, const char __user *buf,
char mybuf[6] = {0};
int i;

- /* Protect copy from user */
- if (!access_ok(buf, nbytes))
- return -EFAULT;
-
if (copy_from_user(mybuf, buf, (nbytes >= sizeof(mybuf)) ?
(sizeof(mybuf) - 1) : nbytes))
return -EFAULT;
--
2.11.0